Oriental bittersweet is a woody vine commonly used for landscaping and holiday decorating. When established, this invasive vine can strangle trees, dominate tree canopies and kill understory plants from lack of sunlight. Because of these invasive qualities, it is illegal for Oriental bittersweet to be transported or sold in Minnesota under the state’s Noxious Weed law. If the vine is found in the state, it should be destroyed or controlled immediately.
Oriental bittersweet is known to be in Stillwater, Red Wing, the Twin Cities and Winona. First confirmed in Minnesota in 2010, new pockets of the vine have been found each year since the initial discovery.
This year, the Legislative-Citizen Commission on Minnesota Resources (LCCMR) recommended funding for survey work by MDA and initial control of existing infestations by Conservation Corps Minnesota.
“As excited as we would be to have funds available to stop existing infestations before they become a statewide problem, we are very concerned with new infestations moving into the state,” said MDA Plant Protection Division Director Geir Friisoe.
“Several of the nation’s largest Oriental bittersweet distributors are next door in Wisconsin, making it easy for the invasive plant to move into Minnesota,” he added.
There is a similar looking alternative to Oriental bittersweet — American bittersweet, which is a non-invasive native plant. Fall and winter are the easiest seasons to distinguish between the two because fruits are clearly visible. American bittersweet fruits have orange fruit capsules; this is the safe variety in Minnesota. The illegal and invasive Oriental bittersweet has yellow fruit capsules. American bittersweet fruits are at the ends of stems; Oriental bittersweet fruits are found all along stems and at leaf axils.
If you find or see bittersweet, make sure that it is American bittersweet. If you suspect it is Oriental bittersweet, bag or burn the material and contact the Minnesota Department of Agriculture.
To view Oriental bittersweet distribution, go to http://go.usa.gov/YBSh. Minnesotans who believe they have found Oriental bittersweet infestations can contact MDA at 1-888-545-6684 or Arrest.the.Pest@state.mn.us.